Manufacture of light hydrocarbons and the like



W. F. RITTIVIAN.

MANUFACTURE OF LIGHT HYDROCARBONS AND THE LIKE.

APPLICATION FILED MAY I8, 1915.

IA]. 9, 121 at nt-ed June 6, 1922.

ATTorNeycame "seams atelier crates.

-war.rn1a r. BITTMAN, or New Year, N. Y., Assreiwoa T srn'rlns'rrc ammo-cannon COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWE.

To all whom it may concern 1 Be it known that I, VVALTER F. RITTMAN', residing at New'York, in the county ofNew York and the State of New York, have invented or discovered certain new and useful Improvements in the Manufacture of Light Hydrocarbonsand the like, of which the following is a specification.

The invention-described herein relates to a process for the manufacture of light hydrocarbons and the/like and has" for its-object the manufacture 'or conversion of such prodor their products but is adapted for the treatment of the liquid hydrocarbons or ucts, either from crude mineral oils, or from the products thereof. The invention is not limited to the treatment of the mineral oils liquid hydrocarbon products obtained from bitumen, shade, coal, lignite, peat, or other substances capable of yielding liquid hydrocarbon products.

Many processes have been employed or suggested for the transformation or eonver sion OffthG above materials into the desired ing a relatively lower boiling point, the

heavy materials-must becracked, which requires. a temperature considerably above the normal boiling point of the material being treated The higher the temperature to which the material is subjected, the larger the percentage of the low'boiling point products produced.

As in distilling operations any increaseof temperature above the normal bollin point of th e liquid cannot be obtained un ess the pressure on the liquids is also increased, a point is soon ireached beyond which the temperature cannot be safely increased.

Practice has shown that .it is difiicult and 'I dangerous to continuouslyemploy a' tern.- perature exceeding40O degrees C. and the necessary accompanying pressure of v above 100 pounds per square inch. *In' order to reduce the dan er incident to. heating large quantities o the heavy materials approximately to 400 degrees .C.,

it has been suggested to atomize the heavy materials prior to subjecting them to such Specification 6f Letters Patent.

MANUFACTURE er near mmaocemaons AND THE LIKE.

Patented June e, ices.

Application filed May 18, 1915. Serial No. 29,020.

temperature in a still. The injection of small quantities of the heavy materials in a finely divided condition into a heated chamber is but a modification of the distilling operation. The material entering the heating chamber is a liquid in finely divided condition, and'this method has the advantage of greatly increasing the surface of evaporation. In the usual distilling method and in the modification referred to, cracking is effected while the material is in a liquid state, and the residue of unconverted heavy material is large. r

It is characteristic of my improved method that cracking is effected after the material has been gasi'fied. The material is trans I formed from a liquid to a gaseous form and then subjected to temperatures at which the gaseous material will be cracked, permitting of the formation of new combinations, the formation of such new combinations being promoted by maintaining the gases under a suitable pressure.

In the practice of my invention the heavy material is continuously fed into a highly heated zone formed by a suitable receptacle in which suitable provision is made whereby the material is flashed or instantaneously transformed into a gaseous condition. The

gases are passed immediately into a zone in which it 1s preferred to 'maintaln a temperavture higher than that in the gasifying zone.

While practice has shown that-a temperature not less than 400 degrees C. should be maintained inv the gasifying zone and an equal, but preferably a much higher,

temperature should be maintained in the second or cracking zone, it will be understood that the temperature in the gasifying and cracking zone will vary with the character ofthe, hydrocarbon materials to be treated, i. e., the higher the boiling points of the material treated, the hi her the tempera-' tures in such-zones shouFd be to attainthe best results. As, for example, it is believed that whentreating materials having boil best repoints above 250 degrees (3., the suits will beattained by maintaining temperatures'of about 550 degrees more orless, inthefrespecti've zones. In the cracking operation; a large numb or differentgases are formed, ranging fromhydrogen to. hydrocarbons havin boiling points the same as or even higher t an those in the materials treated. The cracking per- ,mits of the formation of new and more volatile combinations, the majority of which will be condensable at temperatures of 30 degrees C. and upwards. The maintenance of gases resulting from the cracking, such as hydrogen, methane, ethylene, ethane, etc., having boiling points below 30 degrees C., and which will, for the purposes of this case, be hereinafter termed permanent gases,

in the cracking zone, is an important feature those which remain uncondensed at temperatures of 30 degrees C.,' and above, such as the permanent gases referred to. If the condensable gases be withdrawn 'or removed, the cracking being continued, the other, or permanent gases, or a very considerable proportion thereof. being in the dependent.

high pressures with high temperatures, and.

sphere of reaction, there will be atendency to restore the equilibrium and form the con densable hydrocarbons rather than those not condensable at temperatures above 30 degrees C. This tendency to form the condensable hydrocarbons will be promoted by high concentration or increase of the density of thepermanent gases in the sphere.

of reaction. To this end, a pressure sub stantially above atmospheric'pressure' is maintained in the reaction zone.

'hile the desired pressure can be produced in any suitable manner or by any suitable means, it is preferred to obtain such pressure by controlling the discharge of-the gases from the reaction zone. It will be understood that although the best results can be attained by employing for a given material, a certain temperature and acertain pressure, these two are in no way inter- It is generally preferred to use these pressures and temperatures are generally those whlch cannot be obtained in a two phase system.

lVhile the pressures employed will vary with the character of the material treated, and the character of the products desired,

the best. results will be obtained by maintaining a pressure of about 100 pounds and higher in the generating zone, the efficiency of the process increasing as the pressure employed is increased.

It is only necessary to experimentally de termine the combination of pressure and temperature which yields maximum results.

when applied to the vapours of any particular oil and then apply such combination.

\Vhile a pressure of about 100-lbs. has been indicated, it will be understood that this is'not to be considered as a critical or limiting pressure. This will be apparent (as pointed out in my application Ser. No. 11,398 filed MarJ15, 1915 of which this application is a continuation) from consideration of the equation representing the type reaction.

mAT g B 2C (Concentration B)y+ (Concentration (3)2 Constant where 50A represents the high boiling point hydrocarbons to be converted into lower boiling point hydrocarbons; Where g B represents the lower boiling gasolene hydrocarbons; and 2C- represents hydrogen and non-condensable hydrocarbons (CH C H (1H,, etc.). Physical chemistry recognizes that any such system tends to reach an equilibrium between its various constituents. It is evident that when the end products represented by 2C are kept in the sphere of reaction, the tendency is for mA hydrocarbons to form g B hydrocarbons, in order to satisfy what the chemist terms equilibrium conditions. It is further evident that the greater the concentration of 2C the more pronounced is the tendency of mA to form 1 13 and not form zCf In the conventional type of still these constituents (Concentration A)x termed 2C, being lighter in weight than the liquids, constantly pass up and out of the sphere of reaction; whereas an important feature of this process involves their retention in the sphere of reaction.

It is evident, therefore. that any substantial increase in pressure sufficient to produce a high concentration or increase of density .of. the permanent gases in the sphere of reaction will tend to increase the formation of low-boiling hydrocarbons.

While not necessary it is preferred that gasification should be effected above the re-' action or cracking zone, and that the condensable gases be removed at a point below the cracking zone. so that advantage may be taken of the difference in the character or nature of the permanent and condensable gases, the former being the lighter and therefore having a tendency'to remain in or to return to the reaction zone, as is desired in the-practice of this process.

The shape and dimensionsof the portion of the apparatus .forming the. reaction or cracking zone can be varied within wide limits, but the portion of the chamber forming this zone should be made of a size or dimension suitable for such relative movements of the gases as will promote the separation above referred to, or movements or subsidence of the condensable gases from the cracking zone, and a relatively slower subsidence of such" permanent gases as may be carried along by the condensa'ble gases as theymove away from the cracking zone.

The temperature employed in the practice of my invention depends upon the character of the hydrocarbon material tov be treated, and the character of the products desired. But as it is generally desired to convert as much as possible of the material treated into products having a relatively lower boiling point the temperature employed for gasifying should be sufliciently high to insure the substantially instantaneous gasification of so much of the material as is capable of gasification under practical conditions, and the temperature in the cracking zone should be higher than that in the gasifylng zone, and the conditions above stated will depend in commercial operations largely upon the character of the material treated and the product desired.'

By expanding the heavy hydrocarbons in small quantities into gases and then subjecting these gases to high temperatures and a high pressures, the speed or velocity of reaction incident to high-temperatures is attained without incurring any great liability to. blowouts.

It will ,be understood that in the practice of my invention, the conditions of operation, i. e., temperature, pressure and time, can be changed-and adapted "to produce a desired product in greatermquantity or a diflferent character of product, or either or all of them at will. By reason of having the reaction occur substantially in the gaseous state, a. flexibility in the application of the above conditions is permitted which is impossible in any distillation process, or in any other process involving the retention of liquids in the sphere of reaction. It is well known that in a two-phase system, such as occurs when both liquid and gas are present in the reacting zone, temperature and pressure are interdependent-one being fixed by the condifeed of the material to be generated into gases, or by\ regulating the flow of the converted gases into or from the zone of reaction, or by varying the length of the reaction zone, it is possible to regulate over wide limits, the time or duration of the reactions efi'ected, and regulate at the same time, the pressure and temperature at will, each independent of the other? It is impossible to do this in any two phase system.

lly process is well adapted for the conversion of crude mineral oils or the products thereof, or of liquid hydrocarbons, or liquid hydrocarbon products obtained from bitumen, shale, or other substances capable of yielding liquid hydrocarbon products into gasoline hydrocarbons havingboiling points below 15Q degrees C. The process not only recovers the gasoline hydrocarbons from crude mineral oils originally containing the same, but also material-1y increases the yield thereof, as a very large percentage of the heavy hydrocarbons remaining after the removal ofthe originally contained light hydrocarbons canbe converted into gasoline hydrocarbons having boiling points below 150 degrees C.

The best conditions for the manufacture of gasoline hydrocarbons having boiling points below 150 degrees C. from the above material will be a temperature in the cracking zone ranging approximately between 500 and 700 degrees C, and a pressure of about 300 pounds per square inch andabove.

For the purpose of illustration, I have shown in the accompanying drawing an ex emplification of a simple form of apparatus adapted to the practice of this invention, although it will be understood that the particular apparatus shown is but typical of many others having the same capabilities It is also contemplated that any convenient and etficient source of heat may be substituted for the electricity which I have used in the experimental apparatus.

Figure I is a side view ofthe apparatus,- partly in sections. Figure II illustrates a type of fractional condenser that may be used with this or any similar apparatus.

Referring to the drawing, A indicates a chamber or receptacle capable of withstanding the pressure of the gases within the same and the upper portion of this chamber constitutes the vaporizing section or zone, nil the remaining portion constitutes the hydrocarbon cracking zone. a is a resistance wire, properly insulated, in contact withAv which is incased in-a protective coating of asbestos 'sive radiation of heat.- b and d are binding posts from which -conductors lead to a proper source of electrical energy. 0 is a conducting rod through which one end of the resistence coil is connected to bind post (Z. B is a rheostat used for controlling and regulating the current supplied. 6 is a branch tube opening into A through which the pyrometer couple is introduced whereby the temperature prevailing may be read from an appropriate instrument. f is a rod to support a perforated disc m which supports a quantity of filling material g introduced into the upper portion of A. This filling material may be metal'balls or any 1 other material which will serve as an efficient spreading surface for vaporizing the oil used, as well as a heat conductor and heat disseminator. It will be understood that the use of this filling material is not indispensable to the operation of my invention as the gasification of the material being treated may be facilitated or accomplished by any other suitable means. C is a feed cup or receptacle for supplying oil to A above 9. The pressure in the upper part of C is equalized with that in tube A through an equalizing connection 2. A may also be connected with a suitable gaugefor reading the pressure therein. D is a condenser which leads condensable gases through, a pipe H to a receptacle E- for the collection of liquid distillates. F is a pipe and G a release valve through which the gaseous,

products evolved during the process may be permitted to escape into a gas holder not shown and by shifting this valve the desired pressures may be maintained in the chamher A. In the form of apparatus shown in Fig. 1 a condenser D is cooled to a sufiicient degree to condense all vapors. Condensate passes through H to a collecting vessel E from which said condensate may be withdrawn and fract-ionally distilled. In case a fractional condenser is desiredthe equip ment shown in Fig. 2 would be put in place of E in Fig. 1 and the temperature of condenser D maintained so as to condense only the heavy hydrocarbons and permit the more volatile vapors to pass to a secondary condenser M to be collected in receptacle X.

In the manufacture of gasoline with thetype of apparatus above described and shown in the accompanying drawing. I proceed substantially as follows: The cracking or reacting chamber heated to the. desired cracking temperature of the material by passing an electric current of appropriate wattage through the heating element a. hen the tube A and the filling material 9 contained therein have attained the appro: priate temperature, the feed is opened and the material is permitted to enter the upper part of the tube A where it spreads over the filling material and is flashed or substantially instantaneously transformed into gas.

In the meantime the valve G has been closed in. order to bring the concentration of permanent gases to the desired point. After the desired pressure has been attained valve G can be opened from time to time to release excess pressure created in A. The hydrocarbon gases pass into the cracking zone, of the tube A. After passing through the cracking zone, the hydrocarbon gases are condensed and collected in receptacle E. thereby being removed from the sphere of reaction. v 7

It is characteristic of my improved proc ess that the material treated is gasified, and that cracking is effected in the gaseous phase. And further it is characteristic of the in- -vention that the three conditions which are involved in converting hydrocarbons, i.- e., temperature, pressure and time, are in no way interdependent. That is to say the temperature can be varied without changing the pressure, and vice; versa, and the rate of movement of the gases through cracking or reaction zone can be regulated. In other words. the conditions above stated can be changed simultaneously or independently or in any desired order, or to any desired ,extent, at will, or as required to produce the desired result.

By the term substantially uniform mixture as herein employed.- is meant a mixture containing substantially the entire range of hydrocarbons found in the original liquid material which it is proposedto treat. In other words. all the hydrocarbons from the lightest to the heaviest, regardless of respective boiling points, which are found in the original materiahare converted into gases at substantially the same time so that there is a constant uniformity in the mixture of gaseous hydrocarbons which are to be cracked in the apparatus.

I claim: V 1. In the conversion of high boiling carbon oils into lower boiling hydrocarbon oils. the process which comprises passing the same downwardlythrough a vertical. externally heated, unobstructed chamber under a pressure higher than atmospheric and maintained at a cracking temperature. the

conditions within such retort being such as ed, vertical chamber maintained under heavy pressure and at a cracking temperature and withdrawing produced vapor and gases from the bottom of such chamber.

4. The process herein described which coirsists in subjecting hydrocarbons in a gaseous condition to a temperature of not less than 400 degrees C. and to a pressure of not less than 100 pounds persquare inch and effecting a gravity separation of the mixture and condensing the hydrocarbons having boilin points not lower than 30 degrees C.

5. T e process herein'described which consists in continually passing a substantially uniform mixture of hydrocarbon gases through a heated chamber maintained at a temperature of not less than 400 degrees C. and of such size as to permit of a rapid subsidence of the heavier gaseous hydrocarbons and a relatively slower subsidence of the lighter hydrocarbon gases and in which chamber the gaseous hydrocarbons are sub jected to a pressure of not less than 100 pounds per square inch.

6. The process herein described which consists in continually subjecting a substantially uniform mixture of hydrocarbon gases to a temperature ranging between 500 and 700 degrees C. and to a pressure of about 300 pounds per square inch and upwards and at superatmospheric set my hand.

condensing the gasoline hydrocarbons having boiling'points below 150 degrees C.

7. The process herein described which consists in subjecting a substantially uniform mixture of hydrocarbon gases to a temperature ranging between 500 and 700 degrees C. and to a pressure of about 300 pounds per squareinch and upwards and condensing the gasoline hydrocarbons having boiling points .below 150 degrees C.

8. The process of treating oils containing liquid hydrocarbons having boiling points above 150 C. atatmospheric pressure, to

obtain therefrom low-boiling gasoline hydrocarbons, which comprises vaporizing the oil, passing the substantially of hydrocarbon vapors through an exteruniform mixture nally heated substantially unobstructed ver- WALTER F. RITTMAN. 

